Bengaluru’s Varthur lake has been a festering body of pollutants for a decade now, a product of the city’s rapid expansion and a civic body’s inability to cope with the boom.

Foam blankets the Varthur lake in Bengaluru’s IT hub area. High levels of water pollution cause the water to froth, the toxicity also posing a civic hazard.(HT Photo)

The sight of a frothing lake and tiny foam clouds being blown about by wind might be unusual for most, but for Bengaloreans, it’s just another day by the Varthur lake.

For residents of the area, which is part of the information technology hub of Bengaluru, this has been the reality for a decade.

“For the past 10 years I have lived here, this has been a very common sight,” said M Nagaraj who has lived in the city for 48 years. Before that, the lake was a popular picnic spot. “We used to come here on Sundays to relax.”

The lake was also the area’s main source of water.

“Now we have to rely completely on borewells,” Nagaraj said.

Bengaluru’s lakes – about 600 large and small ones – have been the casualty of the city’s rapid expansion since 2001. According to Census data, the city’s population shot up from about 6.5 million to around 9.6 million between 2001 and 2011, an increase of around 50%. This made it India’s fastest growing city.

This rapid expansion and a lack of preparedness for it is what led to the lakes becoming dump yards for pollutants, said environmentalist AN Yellappa Reddy.

“When authorities allowed constructions in the area during the years the city expanded, they did not make adequate provision for sewage... We have reached a stage where these lakes have become unusable,” he said, adding, “It is water from these lakes that percolates to aquifers, and will eventually pollute groundwater, leading to a bigger disaster.”

Authorities at the Karnataka Lake Conservation and Development Authority refused to comment on the issue.

Urban expert Ashwin Mahesh says the indiscriminate discharge of household waste and industrial effluents into lakes is what causes the toxicity, leading to the water body foaming.

The froth isn’t just an environmental problem; Nagaraj says residents in the area suffer from respiratory problems. Whenever it rains, the lake overflows, spilling the froth onto roads, blocking traffic.

And this isn’t the case just with Varthur lake.

In a study conducted by the Indian Institute of Science in Bengaluru, researchers found that around 90% of the lakes in Bengaluru are affected because of the “sustained inflow of untreated sewage and industrial effluents”.

Mahesh said many experts suggested improving lakes would reduce Bengaluru’s dependence on the use of water from the Cauvery. He recently submitted a report to the government, where he argued that lakes in and around Bengaluru can potentially support 8 million people.

Following repeated demands, the state government announced a fund of Rs 42 crore in the recent state budget for developing lakes.

However, Mahesh said the question of implementation remains. “It is not that the authorities do not know what to do. It is rather a question of will,” he said.